In mobile Internet Protocol (IP), mobile nodes are pre-provisioned with a home agent address. When a mobile node roams to a visited network, a client may attach to a foreign agent. The mobile node would then register with the home network via a foreign agent care-of address. The care-of-address is used by the home agent to send messages to the mobile node. A registration request (RRQ) will then be sent to the pre-provisioned home agent address.
It is likely that millions of mobile nodes are pre-provisioned with the same home agent address. This means that a single physical device must handle the millions of mobile nodes. With a large number of clients roaming to visiting networks, the single physical device may not be able to handle the registration for all of the mobile nodes. However, because the mobile nodes are pre-provisioned with the home agent address, all the registration requests are sent to the single physical device. Thus, the home agent may become overloaded and some of the registration requests may not be timely processed.